Pen



FIG. 1 is a right side elevational view of a pen showing my new design;

FIG. 2 is a front elevational view;

FIG. 3 is a left side elevational view;

FIG. 4 is a view in an exploded condition;

FIG. 5 is a side elevational view of the nib assembly with the pen cap and barrel removed for convenience of illustration;

FIG. 6 is a bottom plan view; and,

FIG. 7 is a top plan view thereof. 

The ornamental design for a pen, as shown and described. 